1. Field of the Invention
The present invention relates to a filtering device and particularly to a disposable dispensing filtering device suitable for use in filtering dissolved and undissolved materials from chemical and biological samples. Especially, the device is useful for use in conjunction with automatic testing and evaluation equipment and kits wherein the sample to be tested is automatically transferred to a test vial which is housed in a base.
2. Description of the Prior Art
In the past, it has been conventional to filter specimens with filtering devices that include a barrel, a plunger slidably disposed in the barrel, and a filter removably disposed on a nipple which is attached to the discharge end of the barrel. The filters which have been conventionally used have a female member which removably engages the nipple. The barrel has usually included a flange at the entry end, that is the end opposite the end having the nipple. This flange aids the user in grasping the barrel to enable the exertion of pressure on the plunger whereby the sample can be urged thrugh the filter and the nipple. Moreover, the inner diameter of the barrel has closely approximated the diameter of the plunger over the entire length of the barrel. Additionally, the top of the nipple was usually exposed so that the filtering device could only rest on its side.